Activity-dependent interactions between motoneurones and muscles: Their role in the development of the motor unit

摘要: In this review article we have attempted to provide an overview of the various forms activity-dependent interactions between motoneurones and muscles its consequences for development motor unit. During early components unit undergo profound changes. Initially two cell types develop independently each other. The mechanisms that regulate their characteristic properties prepare them encounter are poorly understood. However, when axons reach target interaction these cells profoundly affects survival further development. earliest muscle fibres generate a form activity which is in many ways different from seen at later stages. This difference may be due immature ion channels neurotransmitter receptors present membranes both fibres. For example, spontaneous release acetylcholine influence myotube even before any synaptic specialization appears. initial does not necessarily depend on generation action potentials either motoneurone or fibre. Nevertheless, ionic fluxes electric fields produced by such likely activate second messenger systems cells. An important step final distribution contacts primary secondary myotubes reorganization. Mechanisms determine events proposed. It argued layout territory depends matching (possibly myotubes) terminals with relatively weak strength. Such can consequence fibre particular stage maturation will accept only nerve match developmental stage. Refinements follows later. achieved elimination endplates innervated more than one motoneurone. way established, but homogeneity physiological biochemical These gradually, largely as pattern imposed upon supplied given occurs system CNS completes so specialized patterns transmitted they supply.(ABSTRACT TRUNCATED AT 400 WORDS)